fix(Google Gemini Chat Model Node): Add base URL support for Google Gemini Chat API (#12643)

Author: jeanpaul

Diff for: packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleGemini/LmChatGoogleGemini.node.ts

@@ -140,6 +140,7 @@ export class LmChatGoogleGemini implements INodeType {
 
 		const model = new ChatGoogleGenerativeAI({
 			apiKey: credentials.apiKey as string,
+			baseUrl: credentials.host as string,
 			modelName,
 			topK: options.topK,
 			topP: options.topP,